Powered rotary truing device



Oct. 31, 1961 J. G. R. cooPER POWERED ROTARY TRUING DEVICE 3 Sheets-$heet 1 Filed Ofit. 10, 1958 INVENTOR JAMES G. E COOPER 455 1 meatu Oct. 31, 1961 J. G. R. COOPER POWERED ROTARY TRUING DEVICE 5 Sheets-Sheet 2 Filed Oct. 10, 1958 0 0 2 a 4 7 0 M o M MM 4 Z W IHIIIIIU a N m I. M041 Z 5 4 H M m m a J NVENTOR JAMES 6%. Coo/ 52 in mm ATTORNEY United States Patent Ofilice 3,005,332 Patented Oct. 31, 1961 3,066,332 7 POWERED ROTARY TRUING DEVICE James G. R. Cooper, Westboro, Mass., assignor to Norton Company, Worcester, Mass., a corporation of Massachusetts Filed Oct. 10, 1958, Ser. No. 766,591 Claims. (Cl. 1251l) The invention relates to grinding machines, and more particularly to a grinding wheel truing apparatus.

One object of the invention is to provide a simple and thoroughly practical powered rotary truing apparatus. Another object is to provide a positively driven rotatable truing tool which is automatically moved under pressure into operative engagement with a rotating grinding Wheel to be trued.

Another object is to provide a rotatable truing tool having its periphery shaped to produce a desired and predetermined shape on the grinding wheel to be n'ued.

Another object is to provide a grinding wheel truing cycle in which a positively rotated truing wheel is automatically fed into truing engagement with the operative face of a grinding wheel which is rotated at normal grinding speed, and maintaining the truing wheel in operative truing engagement therewith for a predetermined time interval.

Another object is to provide a power driven truing apparatus in which the truing wheel is automatically advanced at the start of each truing cycle, and automatically moved into operative engagement with the wheel to be trued, and maintained in truing engagement therewith for a predetermined time interval.

Another object is to provide means for adjusting the extent of feed imparted to the truing wheel at the start of each truing cycle.

A further object is to provide a timing device to control the extent of the truing operation, and to terminate the truing operation after a predetermined time interval. Other objects will be in part obvious and in part pointed out hereinafter.

On embodiment of the invention has been illustrated in the drawings in which:

FIG. 1 is a front elevation of a portion of a grinding machine showing the improved grinding wheel truing apparatus mounted thereon;

FIG. 2 is a vertical sectional view, taken approximately on the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary sectional view, on an enlarged scale, through the feed gear and the gear type feed pawl therefor;

FIG, 4 is a cross sectional view taken approximately on the line 4-4 of FIG. 3, showing the one-way ball clutch for controlling the pawl gear; and

FIG. 5 is a combined hydraulic and electric diagram of the actuating mechanism and the controls therefor.

A portion of a grinding machine has been illustrated in the drawings comprising a wheel slide which supports a rotatable wheel spindle 11 in suitable journal bearings (not shown) carried by the slide 10. A grinding wheel 12 is mounted adjacent to one end of the wheel spindle 11. The grinding wheel 12 is partially surrounded by a wheel guard 13.

A driving mechanism is provided for the wheel spindle 11 and the grinding wheel 12 comprising a motor '14 which is mounted on the upper surface of the wheel slide 10. The motor 14 is provided with a motor shaft 15 having a multiple V-groove pulley 16 thereon which is connected by multiple V-belts 17 with multiple V-groove pulley 18 which is connected on the right hand end of the wheel spindle 11.

A vertically arranged grinding Wheel truing apparatus frame 20 is mounted on the upper portion of the Wheel guard 13. The frame 20 supports a vertically movable slide 21 on a pair of spaced parallel slide ways 22 and 23 which mate with correspondingly shaped ways on the frame 20.

A rotatable power driven truing wheel 25 which may be a metal bonded diamond impregnated wheel is keyed upon a shaft 26. The shaft 26 is journalled in spaced bearings 27 and 28 which are in turn supported on the lower end of the slide 21. The shaft 26 is connected by a coupling 29 with a shaft 30 which is journalled in a bearing 31. The bearing 31 is mounted on the lower end of a bracket 32 which is fixedly mounted on the slide 21.

The truing wheel 25 is provided with an operative peripheral shaped surface for truing a predetermined contour on the grinding wheel 12. As shown in FIG. 1, the truing wheel 25 is shaped to produce a true cylindrical face which terminates at each end in a radius for use in truing a grinding wheel for a crankpin grinding operation. Other shapes may readily be produced by providing a truing wheel having the desired shape which i the conjugate of the shape to be produced on the periphery of the grinding wheel.

A motor 33 is mounted on a pivotally supported platen 34 which is supported by a rock shaft 35. An adjusting screw 36 is provided adjacent to the lower end of the platen 34 to facilitate adjusting the position of the platen 34 and the motor 33 to tension the driving belt to be hereinafter described. The motor 33 is provided with a motor shaft 37 which supports a gear-shaped pulley 38 which is connected by a cog-belt 39 with a gear-shaped pulley 40 mounted on the right hand end of the shaft 30 (FIG. 1).

A feeding mechanism is provided for moving the slide 21 vertically to move the positively rotating truing wheel 25 into operative engagement with the grinding wheel while the grinding Wheel is rotating at normal grinding speed for a truing operation. The feeding mechanism also serves automatically to impart a predetermined feeding increment to the truing wheel 'at the start of each truing cycle. This mechanism comprises a rotatable feed screw 45 which meshes with or engages a feed nut 46 which is fixedly mounted in the'upper portion of the slide 21. The upper end of the feed screw 45 is supported by an anti-friction bearing 47 which is fixedly mounted relative to the frame 20.

A cylinder 48 is mounted on the upper portion of the frame 20 and contains a slidably mounted piston 49. The piston49 is provided with an anti-friction bearing 50 which connects the upper end of the feed screw 45 to the piston 49, It will be readily apparent from the foregoing disclosure that when fluid under pressure is passed through a pipe 51 into a cylinder chamber 52, the piston 49 together with the feed screw 45 and the slide 21 will be moved upwardly to an inoperative position. During this movement fluid within a cylinder chamber 53 exhausts through a pipe 54.

A fluid pressure system is provided for supplying fluid under pressure to the mechanisms of the truing apparatus. This system comprises a motor driven fluid pump 60 which draws fluid through a pipe 61 from a reservoir 62 and forces fluid under pressure through a pipe 63. A pressure relief valve 64 is connected with the pipe 63 to facilitate exhausting excess fluid under pressure directly through a pipe 65 into the reservoir 62 so as to maintain a substantially uniform operating pressure within the system.

A control valve '66 is provided for controlling the admission to and exhaust of fluid from the cylinder 48. The valve 66 is a piston type valve having a slidably mounted valve member 67 which is provided with a plurality of spaced integral valve pistons to form a plurality of spaced valve chambers 68, 69 and 70. The valve member 67 is also provided with a central passage 71 which interconnects the valve chamber 68 with the valve chamber 70. A compression spring 72 serves normally to hold the valve member 67 in a left hand end position. A solenoid S1 is provided which when energized serves to shift the valve member 67 toward the right to reverse the flow of fluid under pressure between the control valve 66 and V the cylinder 48. A switch SW1 is provided to facilitate stopping and starting the motor driven fluid pump 60.

A safety valve 75 is provided to maintain the truing wheel 25 in a raised position during grinding even in the event of loss of hydraulic pressure. The valve 75 is a pressure actuated piston-type valve comprising a slidably mounted valve member 76 having a plurality of spaced valve pistons formed integrally therewith to form a pair of spaced valve chambers 77 and 78. A compression spring 79 serves normally to maintain the valve member 76 in a right hand end position (FIG.

In the position of the valves 66 and 75, as illustrated in FIG. 5, fluid from the pipe 63 entering the valve chamber 69 passes through the pipe 73, through the valve chamber 77, through a pipe 84, through a ball check valve 85, through the ball check valve 82 and the throttle valve 83, through the pipe 51 into the cylinder chamber 52 so as to raise the piston 49 into the position illustrated in FIG. 5.

When fluid under pressure is passed through the pipe 63 it enters an end chamber 80 and builds up pressure suflicient to move the valve member 76 toward the left against the compression of the spring 79. When the valve member 76 is in a left hand end position fluid under pressure from a pipe 73 passes through the valve chamber 78, through a pipe 81, through a ball check valve 82 and a throttle valve 83, through the pipe 51 into the cylinder chamber 52 to raise and maintain the piston 49 together with the feed screw 45 and the slide 21 into an uppermost or inoperative position. In the event of loss of hydraulic pressure valve member 76 will be moved to the right by spring 79 to the position shown in FIG. 5, so that ball check valve 85 will preclude the discharge of fluid from cylinder chamber 52 necessary to downward movement of piston 49 and the slide 21.

A feeding mechanism is provided for actuating the feed screw 45, either manually or automatically to impart a feeding movement to the slide 21 and the truing wheel 25. A sleeve 90 is slidably keyed to the upper portion of the feed screw 45 and is rotatably supported by the anti-friction bearing 47. A bevel gear 91 is fixedly mounted on the sleeve 90 and meshes with a bevel gear 92 which is mounted on the right hand end of a rotatable shaft 93 (FIG. 2). The shaft 93 is rotatably supported in anti-friction bearings 94 and 95 which are in turn supported by the frame 20. A manually operable feed wheel 96 is slidably keyed onto the left hand end of the shaft 93. An external gear 97 is formed integral with the feed wheel 96 and is arranged to mesh with an internal gear 98 to form a clutch whereby the hand wheel 96 may be disconnected from the power operated feed mechanism, to be hereinafter described, when desired. A compression spring 99 surrounds the left hand end of the shaft 93 and is interposed between a collar fixedly mounted on the left hand end of the shaft 93 and the hub portion of the hand wheel 96. It will be readily apparent from the foregoing disclosure that when a manual adjustment of the slidep21 and the truing wheel 25 is desired, the hand wheel 96 may be moved toward the left against the compression of the spring 99 thereby disengaging the external gear 97 from the internal gear 98 so that a manual rotary motion of the feed wheel 96 in either direction will impart a corresponding movement to the feed screw 45.

' A sleeve or hub 100 is formed integral with a gear '101. The hub 100 and gear 101 are rotatably mounted on the shaft 93 and are pinned to the internal gear 98.

The hub serves as a support for a feed arm 102. The feed arm 102 supports a stud 103 which in turn supports a rotatable gear-type pawl 104. The gear 104 is connected with the stud 103 by a one-way roller clutch 105 which is arranged so that when the feed arm 102 is moved in a clockwise direction, the gear 104 is held against rotary motion in a clockwise direction and imparts a clockwise feeding movement to the feed gear 101. When the feed arm 102 is moved in a counter-clockwise direction to reset the feeding mechanism, the roller clutch 105 allows the gear 104 to ride idly over the teeth of the feed gear 101.

A holding pawl is provided for preventing counterclockwise movement of the feed gear 101 (FIG. 1) during the resetting of the feed arm 102. The holding pawl, as illustrated in FIG. 1 comprises a gear 106 which meshes with the feed gear 101. The gear 106 is supported by a stud 107 which is in turn mounted on an adjustable arm 108. The arm 108 is supported by a stud 109. A oneway roller clutch, the same as that shown in FIG. 4, is provided between the stud 107 and the gear 106. This roller clutch is arranged so that the gear 106 is free to rotate in a counter-clockwise direction when a clockwise feeding movement is imparted to the feed gear 101. This roller clutch is also arranged so that during a resetting movement of the feed pawl gear 104, the gear 106 is held against rotation relative to the stud 107 so that the feed gear 101 can not turn in a counter-clockwise direction.

A hydraulically operated mechanism is provided for actuating the feed arm 102 comprising a cylinder which is fixedly mounted on a plate 116 which is supported in fixed relation with the truing apparatus base or frame 20. The cylinder 115 contains a slidably mounted piston 117 which is connected to a double end piston rod 118. The left hand end of the piston rod 118 is connected by a stud 119 with a link 120. The other end of the link 120 is connected by a stud 121 with the feed arm 102. The link 120 is preferably a two part link having a screw adjusting mechanism 122 in its central portion to facilitate adjusting the length of the link 120 so as to facilitate adjusting and setting up the feed mechamsm.

The piston rod 118 is provided with an adjustably mounted collar 123 which is arranged to engage a stop surface 124 on the right hand end of the cylinder 115 when the piston is moved toward the left. The collar 123 is adjustably mounted so that the stroke of the piston 117 may be varied so as to facilitate varying the extent of the feed increment imparted to the feed gear 101 at each actuation of the piston 117.

The flow of fluid to and from the cylinder 115 is preferably controlled by the control valve 66. In the position of the control valve 66 (FIG. 5) fluid under pressure passing through the pipe 73 passes through a throttle valve 126 and a ball check valve 127 and through a pipe into a cylinder chamber 128 so as to move the piston 117 toward the right thereby imparting a counter-clockwise movement to the feed arm 102 to reset the pawl gear 104. During this movement fluid within a cylinder chamber 129 exhausts through the pipe 54 into the valve chamber 70, through the central passage 71 into the valve chamber 68 and through a pipe 74 into the reservoir 62.

Similarly when the valve member 67 is in a right hand end position fluid under pressure entering the valve chamber '69 passes through the pipe 54 into the cylinder chamber 129 to move the piston'117 toward the left (FIG. 5) at a rate controlled by the throttle valve 126. During this movement fluid within the cylinder chamber 128 exhausts through the pipe 125, through the throttle valve 126, through the pipe 73 into the valve chamber 68 and through the pipe 74 into the reservoir 62. This movement of the piston 117 serves to impart a clockwise movement to the feed arm 102 thereby imparting a rotary motion to the feed screw 45 to feed the slide 21 together soonest with the truing wheel 25 downwardly by a predetermined increment. By manipulating the throttle valve 126 the rate of the down feeding movement may be readily controlled.

The pawl gear 104 together with its supporting stud 103 are preferably mounted on a bracket 130 pivotally supported by a stud 131 upon the feed arm 102. A stop screw 132 on the bracket 130 (FIG. 1) serves to limit the adjusting movement of the bracket 130 relative to the feed arm 102. A clamping screw 133 extending through an elongated slot in feed arm 102 is provided to lock the bracket 130 in adjusted position. This adjustment is provided to facilitate adjusting the meshing of the pawl gear 104 with the feed gear 101.

A coolant fluid system is provided for supplying coolant or cutting fluid to the truing wheel 25 and the grinding wheel 12 comprising a pipe 140 which is slidably mounted in a bearing 141. The lower end of the pipe 140 is provided with a nozzle 142 located and positioned to direct coolant or cutting fluid onto the periphery of the truing wheel 25 adjacent to the line of contact between the cutting wheel 25 and the grinding wheel 12.

It is desirable to maintain the nozzle 142 in a predetermined relationship with the truing wheel 25 and the slide 21 as the slide 21 moves to lower positions as the grinding wheel 12 wears away due to grinding and truin As illustrated in the drawing the slide 21 is providedwith a projection lug 14 3 which engages the upper face of the nozzle 142 (FIG. 2). A yieldable means is provided for maintaining the nozzle 142 in engagement with the lug 143 comprising a tension spring 144. The upper end of the spring 144 is connected to a stud 145 which is fixed relative to the frame 20. The lower end of the spring 144 is connected to a stud 146 which is fixedly mounted on the pipe 140. In order to hold the pipe 140 against rotary motion, the collar 147 is provided with a pin 148 which rides in an elongated slot or groove 149 formed in a webbed portion 150 of the frame or base 20. It will be readily apparent from the foregoing disclosure that when the slide 21 is fed downwardly to position the truing wheel 25 in operative engagement with the periphery of the grinding wheel 12 as the grinding wheel wears away, the lug 143 will cause a downward movement of the pipe 140, against the tension of the spring 144, so as to maintain the nozzle 142 in the same relative position with respect to the truing wheel 25.

The operation of the improved truing apparatus will be readily apparent from the foregoing disclosure. Assuming the mechanisms to have been previously adjusted, a switch SW2 is closed to start the grinding wheel drive motor 14. The switch SW1 may be manually closed to start the motor driven pump 60 which serves to convey fluid under pressure through the pipe 63 into the cylinder chamber 52 so as to position and to maintain the truing wheel 25 in an uppermost or inoperative position until a truing cycle is initiated.

When it is desired to start a truing cycle, a push button switch FBI is closed to energize an electric-timer T1. The timer T1 may be any of the well known commercial timer such for example, Microflex automatic reset timer manufactured by Signal Electric Company of Moline, Illinois. The energizing of the timer T1 closes the contacts CCl, RC1, and RC2. The closing of the contacts RC1 of the timer T1 serves to energize the relay switch CR1 to start the truing wheel driving motor 33. The closing of the contacts RC2 of the timer T1 serves to energize the solenoid S1 to shift the valve member 67 into a right hand end position thereby passing fluid under pressure from the valve chamber 69, through the pipe 54 into the cylinder chamber 129 to impart a feeding increment to the feed gear 101. At the same time fluid under pressure passing through the pipe 54 enters the cylinder chamber 53 to feed the piston 49 together with the slide 21 and the truing wheel 25 downwardly into truing engagement with the grinding wheel 12 to be il'l ld.

The lower end of the piston 49 is provided with a cushioning means comprising a dash-pot piston which slides within a dash-pot cylinder 136. During the initial downward movement of the piston 49 fluid within a dashpot cylinder chamber 137 may exhaust through a port 138 into the cylinder chamber 52 and thence through pipes 51, 73, and 74 to reservoir 62. As the piston 135 moves downwardly, it restricts the flow of fiuid through port 138, so as to cushion the downward movement of the piston 49. The initial downward movement of the piston 49 is also controlled by manipulation of the throttle valve 83. This dash-pot mechanism serves to facilitate forcing the rotating truing wheel 25 into truing engagement with the grinding wheel 12 at a controlled rate.

The truing wheel 25 remains in truing engagement with the grinding wheel 12 for a predetermined time interval as governed by the timer T1. After a predetermined time interval has elapsed, the contacts CC1, RC1 and RC2 open. The opening of the contacts 0C1 resets the timer T1 to take it ready for the next truing cycle, the opening of the contacts RC2 serves to deenergize the solenoid S1 so that the compression of the spring 72 may move the valve member 67 into a left hand end position, as shown in FIG. 5, thereby passing fluid under pressure into the cylinder chamber 52 to move the piston 49 together with the slide 21 and the truing wheel 25 into an upper-most or inoperative position. At the same time fluid under pressure passes into the cylinder chamber 128 to move the piston 117 toward the right, into the position illustrated in FIG. 5, thereby resetting the feed arm 102 and the pawl gear 164. Simultaneously the opening of the contacts RC1 serves to deenergize the relay switch CR1 thereby stopping the truing tool driving motor 33.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As' many possible embodiments may be made of the invention and as many changes might be made in the embodiments above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings are to be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A grinding wheel truing apparatus for grinding machines having a rotatable grinding wheel, means for rotating said grinding wheel at the normal grinding speed, a truing apparatus therefor including a base, a slide on said base which is movable toward and from the grinding wheel, a motor driven rotatable truing wheel on said slide, a feeding mechanism to move said slide to advance the truing tool, a positioning mechanism to move said slide rapidly to position the rotating truing wheel into operative engagement with the grinding wheel while said grinding wheel is rotating at the normal grinding speed, means simultaneously to actuate the feeding and positioning mechanisms to initiate a truing cycle and means automatically to reset said feeding mechanism and to separate the truing wheel from the grinding wheel after a predetermined truing operation.

2. A grinding wheel truing apparatus for grinding machines having a rotatable grinding wheel, means for rotating said grinding wheel at the normal grinding speed, a truing apparatus therefor including a base, a slide on said base which is movable toward and from the grinding wheel, a motor driven rotatable truing wheel on said slide, a feeding mechanism to impart an incremental feeding movement to said slide to advance the truing wheel for a truing operation, a positioning mechanism to move said slide rapidly to position the rotating truing wheel into operative engagement with the grinding wheel while said grinding wheel is rotating at the normal grinding speed, means simultaneously to actuate the feeding and positioning mechanisms to initiate a truing cycle, and means including a timing device operatively connected to reset the feeding mechanism and the positioning means after a predetermined truing operation has been completed.

3. A grinding wheel truing apparatus for grinding machines having a rotatable grinding wheel, driving means for rotating said grinding wheel at the normal grinding speed, a truing apparatus therefor including a base, a slide on said base which is movable toward and from the grinding wheel, a motor driven rotatable truing wheel on said slide, a feeding mechanism operatively connected to move said slide to advance the truing wheel, means including a piston and cylinder operatively connected to move said slide rapidly to position the rotating truing wheel in operative engagement with the grinding wheel while said grinding wheel is rotating at the normal grinding speed, means including a fluid pressure actuated mechanism to impart an incremental feeding movement to said feed mechanism, a control valve operatively connected simultaneously to actuate said feed mechanism and to admit fluid under pressure to said cylinder to cause a rapid approaching movement to said truing wheel, and means including an electric-timer operatively connected to control said valve so as to control the duration of the truing cycle.

4. A grinding wheel truing apparatus for grinding machines having a rotatable grinding wheel, driving means for rotating said grinding Wheel at the normal grinding speed, a truing apparatus therefor including a base, a vertically movable slide thereon, a motor driven rotatable cutting truing wheel on said slide, a nut and screw feeding mechanism for said slide, means including a piston and cylinder operatively connected to move said screw axially to position the rotating truing wheel in operative to said nut and screwtmechanism, a control valve operatively connected simultaneously to actuate said pawl and ratchet mechanism and to admit fluid under pressure to said cylinder to cause a rapid approaching movement to said truing wheel, and means including an electric timer operatively connected to control said valve so as to control the duration of the truing cycle.

5. A grinding wheel truing apparatus for grinding machines having a rotatable grinding wheel, driving means for rotating said grinding wheel at the normal grinding speed, a truing apparatus therefor including a base, a vertically movable slide thereon, a motor driven rotatable cutting truing wheel on said slide, a nut and screw feeding mechanism for said slide, means including a piston and cylinder operatively connected to move said screw axially to position the rotating truing wheel in operative engagement with the grinding wheel while said grinding wheel is rotating at the normal grinding speed, means including a pawl and ratchet mechanism to impart an incremental feed to said nut and screw mechanism, a piston and cylinder to actuate said pawl and ratchet, a control valve operatively connected simultaneously to both of said cylinders to impart an incremental feeding movement and to cause a predetermined rapid approaching movement to said truing wheel, and means including an electric timer operatively connected to control said valve so as to control the duration of the truing cycle.

References Cited in the file of this patent UNITED STATES PATENTS 1,896,533 Vuilleurnier Feb. 7, 1933 2,385,644 Polk Sept. 25, 1945 2,443,789 Flygare June 22, 1948 2,601,290 Hopkins et a1 June 17, 1952 2,652,661 Flanders Sept. 22, 1953 2,877,758 Fassnacht Mar. 17, 1959 FOREIGN PATENTS 601,030 Great Britain Apr. 16, 1948 

